Tech talk

[Mr Kurtz]

I like F1 because I basically love fast cars. But I'm fascinated with the technology and for me that makes the other half why I watch it. But unfortunately you can't always see the 'real' differences between the cars. So I thought that if you guys see great pictures from the different rear suspensions etc you could post them here.
Reviewing some pictures from testing, I noticed that there are distinct differences in the front suspension of the teams. Toyota and BMW have upper wishbones that are going up closer to the car, Ferrari and Mclaren for instance have horizontal upper wishbones and if you look at the Renault, they're going downwards. I wonder what works best with the new Bridgestones.

BMW : http://images.gpupdate.net/large/68404.jpg
Toyota : http://images.gpupdate.net/large/68397.jpg
Ferrari : http://images.gpupdate.net/large/68401.jpg
McLaren : http://images.gpupdate.net/large/68399.jpg
Red Bull : http://images.gpupdate.net/large/68398.jpg
Renault : http://images.gpupdate.net/large/68400.jpg

[tinchote]

I know little or nothing about all this. I wonder whether those angles you mention are a fixed feature of each car, or they can be altered for different setups.

[wmcot]

I see what you mean from the pictures posted. I would love to hear from someone who is knowledgeable about this subject! It's refreshing to actually LEARN something from these forums...

[Gannex]

The angle of the wishbones is determined by two factors: the method of mounting the lower wishbone, and the height above ground of the forward monocoque.

The big decision is whether to have zero-keel, twin-keel, or v-keel as mounting for the lower of the front wishbones. This has been one of the big issues in F1 design ever since Sauber stunned the F1 world with its twin-keel design about five years ago. Until then, every car had the lower wishbones attach to a single keel under the monocoque. This was a very rigid arrangement (rigidity is good) and light in weight as well. But it placed a keel (and the wishbones themselves) directly behind the front wing, spoiling the airflow behind the front wing, and thereby reducing the downforce of the wing, as well as increasing the drag. That is why Sauber developed a twin keel arrangement: it left a tunnel behind the front wing, smoother airflow and higher downforce.

But a twin-keel arrangement had a severe problem: it flexed. To eliminate the flex (which changes suspension geometry by very small amounts, and therefore sacrifices control of the contact patch of the tyres), designers found they had to beef up the two keels. Beefing them up made them heavier and larger, meaning you move the centre of gravity of the car forward, and you increase the drag associated with the keels themselves. So Sauber's innovation was not copied by everyone, Ferrari being the most notable hold-out.

By 2005 or so, almost everyone had moved to some version of the twin-keel arrangement to take advantage of the improved downforce at the front and the smoother airflow toward the rear of the car, under the monocoque. Call these arrangements twin-keel or V-keel, or whatever, the fact was that they allowed the lower wishbone to be mounted the same height above ground at both ends: at the keel, and at the wheel. This gives you a horizontal lower wishbone which, in a perfect world, is exactly what you want.

Adrian Newey, however, found a better way, and it made its debut on the 2005 McLaren. It did away with the keels altogether, anchoring the upper wishbone into the monocoque (hardly revolutionary), but anchoring the lower wishbone into the monocoque as well !!! This could only be done by lowering the droop of the nose, and even then, the lower wishbone was slanted upwards to meet the monocoque, rather than parallel to the ground, as it would have been if it had been anchored to a keel. That's why the 2005 McLaren was the first car to have droopy front suspension linkage: high at the centre, sloping downwards towards the wheels.

The McLaren zero keel was a bold breakthrough design, and its obvious advantage was that there was now no keel at all, no superstructure at all interfering with the airflow behind the front wing. Even the V-keel arrangements had some disruptive effect on the front wing exiting air, but the zero-keel let that air flow smoothly and quickly backwards -- exactly what you want.

But what about that droop that a zero-keel imparts? Is that not a problem? Suspension settings indeed become very difficult. Keeping the contact patch large during all conditions becomes increasingly complex, and this is the large drawback to the zero-keel design: it makes front suspension set-up very difficult. If it's correct for a fast corner, it's incorrect for a slow one. As the car rolls (i.e., rotates around its longtitudinal axis), controlling the effects of the roll become infinitely more complex. McLaren were initially alone in having the zero keel with its droopy suspension.

But not any more!!! Everyone and their brother seems to have seen the Newey light. Even super-conservative Toyota now have a zero keel arrangement on their 2007 car. So the F1 car, in its standard configuration, now has droopy front suspension wishbones, and each design deals with this problem in a different way. Note the complex kinks in the Toyota wishbone, for example.

There are two exceptions to this design trend and the most surprising thing is that the designer who has most clearly rejected zero-keel is the very man who invented it, Adrian Newey. This year's Red Bull, which is Newey's design, goes back to twin keel, meaning that Red Bull has its suspension wishbones nice and parallel as nature intended.

The second design to go against the zero-keel trend is Renault. They have a V-keel arrangement, so that they too will benefit from the logical suspension geometry that you get when you don't have to slope your lower wishbone upwards to meet the monocoque.

These new suspension arrangements have to work, of course, with a totally new construction of front tyre, and it is here that the dissidents, Renault and Red Bull, might have hit the jackpot. Winter testing with the new Bridgestone tyres has shown that they, especially the fronts, are extremely low in grip compared to last year's tyre. Bridgestone have been quite honest about it, admitting that the construction is designed to sacrifice grip for sturdiness, reliability and safety. But the drivers are finding it very difficult to adapt to this year's Bridgestone fronts. Braking distances, for example, have had to be extended massively, to avoid front-wheel lock-up.

So with the new Bridgestones it appears that a straightforward front geometry becomes even more important than it was last year. At that very point, all the teams except Red Bull and Renault have moved onto droopy suspension arrangements, zero-keel, which makes suspension set-up tricky. That's why Red Bull and Renault's return to conservative old-fashioned suspension geometry might have come at exactly the right moment.

[Roamy]

gannex

this is very very good stuff !!!!!!!!!!

[Gannex]

Why thank you, fousto. And you said that even though I made not one reference to JV's genius!

[mstillhere]

That's what I call a detailed information.

[mstillhere]

That's what I call a detailed information.

[mstillhere]

That's what I call a detailed information.

[mstillhere]

Sorry for the multiple postings. I had a little issue with my browser.